Should We Cull “Invading” Lionfish?

While there are multiple sides to every issue, there are some very convincing arguments supporting removal of lionfish from Atlantic waters. Before we get into the detailed reasons, we should understand this is not a natural migration of lionfish into a new area, rather an introduction caused by man. Lionfish are extremely popular aquarium fish, and the same reasons that make them a burden to keep –– ravenous feeders with venomous spines –– position them to be perfectly suited as invaders in Atlantic and Caribbean waters.

Based on the recent work of Reef Environmental Education Foundation and researchers James Morris, Stephanie Green, Mark Hixon and others, we know that lionfish in the Atlantic: grow quickly, reaching maturity at less than a year of age; reproduce year-round with up to 30,000 eggs per spawning event (every four days); eat almost any prey that will fit in their mouth (up to half their own body size); feed on commercially and ecologically important species including grouper/snapper, parrotfish, cleaner species; have few if any predators in the Atlantic; and are reaching incredible densities up to 20 times higher than similar-size native species. The bottom line is that they are out-competing our native fish and consuming them at unsustainable rates.

Invasive species are the primary cause of extinction of other organisms, surpassing even human impacts. Could lionfish cause extinction of our native species? We can’t be sure, but the scenario is likely and once it happens it will be too late to reverse the change. And what of the consequences of those losses? If cleaner species –– which have been found in lionfish stomachs –– are impacted, we will likely see cascading effects through the rest of the fish community. If commercially valuable species like grouper and snapper are impacted, the effects will also reach local economies and communities through diminished fisheries and food supplies. If parrotfish and other algae eaters are impacted, the effects on corals themselves will likely be significant. Will equilibrium eventually be reached? Absolutely, but what will the system look like and are we willing to live with those consequences?

We can paint a dramatic and scary picture from what we now know. What we cannot yet predict, though studies are addressing this now, is how effective we can be in controlling lionfish populations and minimizing impacts. Tagging work led by REEF has shown very high site fidelity in lionfish –– they tend to stay put as long as there is food and shelter. This makes them a perfect candidate for removal. What we don’t yet know is how much effort will be required to remove lionfish and how many lionfish a reef can sustainably support. In addition, novel control methods are currently being explored that could provide efficient means of removal. The best part of removal? Lionfish are a very good eating fish. Combining removal efforts with the development of commercial use and markets can prove to be a win-win situation, which rarely occurs in invasive species scenarios. Programs are already in place or being developed in the U.S., Bermuda, Bahamas, Turks and Caicos and Cuba to encourage lionfish consumption. As those in Bermuda say, “Eat ’em to beat ’em!”